Sickle cell disease is a genetic disorder which affects the red blood cells (RBCs). The RBCs of people with sickle cell disease contain a different form of hemoglobin called haemoglobin ‘S’. This is an abnormal type of hemoglobin and RBCs containing this hemoglobin become sickle shaped. They also become stiff and due to their distorted shape they have difficulty in passing through small blood vessels. When these sickle cells, thus block the blood vessels, less blood reaches that part of the body. Tissue that does not receive the normal blood flow eventually gets damaged. This is the main cause of the various complications including increased incidence of infections encountered in sickle cell disease.
The normal RBCs containing normal hemoglobin (called ‘Hemoglobin A’) not only are soft and round but also live up to about 120 days before new ones replace them. However, the RBCs from people suffering from sickle cell disease hardly have a life of about 10 -20 days. The bone marrow can not make the new red blood cells fast enough to replace the dying ones. This results in severe anemia, which is one of the main symptoms of this disease. Sickle cell anemia affects millions of people worldwide.
Sickle cell disease is an inherited, life-long condition. People who have sickle cell anemia are born with it. They inherit two copies of the sickle gene from each parent. Sickle cell disease is prevalent world over including India. The major features of the sickle cell disease encountered in these patients include chronic fatigue, severe anemia, pain crises, bacterial infections, lung, liver and heart injury, leg ulcers, damage to the eye, inflammation of the hands and feet, arthritis, splenomegaly and chronic lung infections etc.
Sickle cell trait is an inherited condition in which both Hemoglobin A and Hemoglobin S are produced in Red Blood Cells, always more ‘A’ than ‘S’. people with Sickle cell trait may also develop some complications at a later stage in life. Under unusual circumstances serious morbidity and mortality can result from polymerization of de-oxy hemoglobin S; these complications include increased urinary tract infections in women, gross hematuria, complications of hyphema, splenic infarction with altitude hypoxia or exercise and life threatening complications of exercise, excertional heat illness or idiopathic sudden death. In addition, certain disease associations have been noted with sickle cell trait—such as early end stage renal failure, renal medullary carcinoma and polycystic kidney disease.
Though efforts have been made to control many of the symptoms and complications of the disease, the results are far from satisfactory in providing lasting cure and comfort to the sickle cell patient. Usually the health maintenance for these patients starts with early diagnosis, preferably in the newborn period and includes penicillin prophylaxis, vaccination against potential bacterial disease and folic acid supplementation. Treatment of complications often includes antibiotics, pain management, intravenous fluids and surgery all backed by psycho-social support. Blood transfusions help sickle cell disease patients by reducing recurrent pain crisis, risk of stroke and other complications. Because blood cells contain iron, and there is no natural way of eliminating excess iron, patients who receive repeated blood transfusions accumulate iron in the body till it reaches toxic levels.
A constant search is going on to find a substance which can stop sickling of RBCs or which can at least offer lasting symptomatic relief to a patient with sickle cell disease. One of the most promising drugs for this condition was Hydroxyurea, which is essentially an anti-cancer drug. Hydroxyurea has been shown to reduce the painful crises and acute chest syndrome in adults and to lessen the need for blood transfusions. Hydroxyurea seems to work by increasing the fetal hemoglobin in the RBCs. But being a potent anti-cancer drug, it has its own side effects. The major side effects of Hydroxyurea include decreased production of platelets, red blood cells and white blood cells. The effects of long term Hydroxyurea is yet to be established.
Bone marrow transplantation is another procedure which is being tried in sickle cell disease, mainly in severely affected children. Though it may give dramatic results, its routine use is not possible because of the complications associated with the procedure besides the high cost and the need for highly sophisticated infrastructure and appropriate donors.
Efforts are being made to search for natural and herbal products which can offer therapeutic effect in sickle cell disease without producing undue adverse effects.
Vanillin, a food additive, has been evaluated as a potential agent to treat sickle cell disease. Studies have indicated moderate antisickling activity when compared to other aldehydes. Abraham et al; PMID2001455.
A phytochemical formulation has been patented in US by National Institute for Pharmaceutical Research and Development Federal Ministry of Science and Technology (Ahuja, NG). The composition is a cold water extraction product of a mixture containing Piper guineenses seeds, Pterocarpusosum stem, Eugenia caryophyllum fruit, Sorghumbicolor leaves and potash. Though promising, more clinical studies are required before the safety, efficacy of the formulation could be established. (U.S. Pat. No. 5,800,819 )
There is also a mention of hydration of sickle erythrocytes using a herbal extract (pfaffia paniculata) in vitro (British J.Haematology (2000 ); 111359-362)
Sickle cell disease is an international health problem and truly a global challenge. Hence efforts are being made to find out an ideal therapy which is effective and at the same time also safe. But so far none of the medications or procedures as described earlier have come anywhere close to what is desirable.